Rajasekaran Sivashankari P, Huynh Bao, Fugolin Ana Paula P
Division of Biomaterials & Biomedical Sciences, Department of Oral Rehabilitation and Biosciences, School of Dentistry, Oregon Health & Science University, 2730 S Moody Ave., Portland, OR 97201, USA.
J Funct Biomater. 2024 Apr 27;15(5):117. doi: 10.3390/jfb15050117.
Cargo encapsulation through emulsion-based methods has been pondered over the years. Although several microemulsification techniques have been employed for the microcapsule's synthesis, there are still no clear guidelines regarding the suitability of one technique over the others or the impacts on the morphological and physicochemical stability of the final particles. Therefore, in this systematic study, we investigated the influence of synthesis parameters on the fabrication of emulsion-based microcapsules concerning morphological and physicochemical properties. Using poly(urea-formaldehyde) (PUF) microcapsules as a model system, and after determining the optimal core/shell ratio, we tested three different microemulsification techniques (magnetic stirring, ultrasonication, and mechanical stirring) and two different cargo types (100% TEGDMA (Triethylene glycol dimethacrylate) and 80% TEGDMA + 20% DMAM (N,N-Dimethylacrylamide)). The resulting microcapsules were characterized via optical and scanning electron microscopies, followed by size distribution analysis. The encapsulation efficiency was obtained through the extraction method, and the percentage reaction yield was calculated. Physicochemical properties were assessed by incubating the microcapsules under different osmotic pressures for 1 day and 1, 2, or 4 weeks. The data were analyzed statistically with one-way ANOVA and Tukey's tests (α = 0.05). Overall, the mechanical stirring resulted in the most homogeneous and stable microcapsules, with an increased reaction yield from 100% to 50% in comparison with ultrasonication and magnetic methods, respectively. The average microcapsule diameter ranged from 5 to 450 µm, with the smallest ones in the ultrasonication and the largest ones in the magnetic stirring groups. The water affinities of the encapsulated cargo influenced the microcapsule formation and stability, with the incorporation of DMAM leading to more homogeneous and stable microcapsules. Environmental osmotic pressure led to cargo loss or the selective swelling of the shells. In summary, this systematic investigation provides insights and highlights commonly overlooked factors that can influence microcapsule fabrication and guide the choice based on a diligent analysis of therapeutic niche requirements.
多年来，人们一直在思考通过基于乳液的方法进行货物封装。尽管已经采用了几种微乳化技术来合成微胶囊，但对于一种技术相对于其他技术的适用性，或者对最终颗粒的形态和物理化学稳定性的影响，仍然没有明确的指导方针。因此，在这项系统研究中，我们研究了合成参数对基于乳液的微胶囊制备过程中形态和物理化学性质的影响。以聚（脲 - 甲醛）（PUF）微胶囊作为模型系统，在确定最佳核/壳比后，我们测试了三种不同的微乳化技术（磁力搅拌、超声处理和机械搅拌）以及两种不同的货物类型（100% 三乙二醇二甲基丙烯酸酯（TEGDMA）和80% TEGDMA + 20% N,N - 二甲基丙烯酰胺（DMAM））。通过光学显微镜和扫描电子显微镜对所得微胶囊进行表征，随后进行尺寸分布分析。通过萃取法获得包封效率，并计算反应产率百分比。通过在不同渗透压下将微胶囊孵育1天以及1、2或4周来评估其物理化学性质。使用单向方差分析和Tukey检验（α = 0.05）对数据进行统计分析。总体而言，机械搅拌产生的微胶囊最均匀且稳定，与超声处理和磁力方法相比，反应产率分别从100%提高到了50%。微胶囊的平均直径范围为5至450 µm，超声处理组中的微胶囊最小，磁力搅拌组中的最大。封装货物的亲水性影响微胶囊的形成和稳定性，DMAM的加入导致形成更均匀、更稳定的微胶囊。环境渗透压导致货物损失或壳的选择性膨胀。总之，这项系统研究提供了见解，并突出了一些通常被忽视的因素，这些因素会影响微胶囊的制备，并基于对治疗需求的仔细分析来指导选择。
